Idling regulator for internal-combustion engine carburetors

ABSTRACT

A regulator provided with an inertia-block resiliently connected to a slidable pressure-responsive member controls automatically the feeding of fuel to the idling jet of a carburetor, in response to pressure variations in the inlet manifold of an internal-combustion engine. Consequently air pollution by unburnt fractions of the exhaust gases at idling speed and during deceleration is substantially prevented.

United States Patent Inventor Claude Chavant Issy Les Moullneaux, France Applv No. 59,618 Filed July 30, 1970 Patented Jan. 4, 1972 Assignee Chrysler France Paris, France Priority Oct. 16, 1969 France IDLING REGULATOR FOR INTERNAL- COMBUSTION ENGINE CARBURETORS 8 Claims, 2 Drawing Figs.

U.S. Cl .7 123/97 B Int. Cl F02d 9/00 Field of Search 123/97 B,

124, 119 D, 119 DB [56] References Cited UNITED STATES PATENTS 2,877,997 3/1959 Kane, Jr. et a1. 123/97 B 2,879,046 3/1959 Dolza et al 123/97 B 2,895,561 7/1959 McCollough 123/97 B 3,470,855 10/1969 Von Seggem et al 123/97 B Primary Examiner-Wendell E. Burns Attorney-Kenyon & Kenyon Reilly Carr & Chapin ABSTRACT: A regulator provided with an inertia-block resiliently connected to a slidable pressure-responsive member controls automatically the feeding of fuel to the idling jet of a carburetor, in response to pressure variations in the inlet manifold of an internal-combustion engine. Consequently air pollution by unbumt fractions of the exhaust gases at idling speed and during deceleration is substantially prevented.

PAIENTED JAN 41912 IN VEN Ton C4 A (/05 can VAN? away ,4 TTORA/EXS IDLING REGULATOR FOR INTERNAL-COMBUSTION ENGINE CARBURETORS The present invention relates generally to the feeding of intemal-combustion engines with fuel mixture and is concerned more particularly with a device for automatic control of the feeding of the idling jet of an engine fed by a carburetor.

The unburnt or insufficiently burnt gases produced by internal-combustion engines, in particular those fitted on automotive vehicles, contribute to a considerable extent to atmospheric pollution. While the design and regulation of modern carburetors enable to avoid to a great extent the production of unburnt gases when the engine runs under steady operating conditions corresponding for instance to the cruising speed of an automotive vehicle, the same does not occur during sharp speed variations and in particular during abrupt decelerations leading to sudden and considerable increase of the vacuum prevailing in the inlet manifold of the engine; consequently, the gasoline in the idling circuit of the carburetor is sucked into the cylinders, where the amount of available air is then not sufficient to ensure complete combustion. Consequently, the exhaust gases include a high proportion of unburnt or insufficiently burnt hydrocarbons, resulting in atmosphere pollution, inconsistent with the standards provided for in certain countries.

In order to obviate this well-known drawback, it has been suggested to close the feeding circuit of the idling jet of the carburetor in case of abrupt deceleration, by means of an electric system controlled for instance from a pressure-responsive capsule mounted in the inlet manifold. The devices of this type are however relatively complicated, frangible and costly and, moreover, may interfere with the normal operation of the engine at transitory speeds.

The invention has for its object to provided an automatic device formed of a small number of simple, steady and lowcost mechanical members serving to regulate the supply of fuel to the idling regulator of the carburetor feeding an internal-combustion engine, in accordance with the speed variations of the said engine. More particularly, the invention has for its object to provide such a device serving in particular to interrupt the flow of fuel to the idling jet in case of abrupt deceleration.

The idling regulator according to the invention is characterized in that it comprises an inertia-block resiliently connected to a movable pressure-responsive member subjected to the pressure difference between for instance the carburetor and the inlet manifold, and means for controlling the feeding of the idling jet with fuel, actuated by the displacements of the said pressure-responsive member and the said inertia-block in response to variations in the said pressure difference.

Thus, the idling regulator according to the invention is not only responsive to the differential pressure between the carburetor and the inlet manifold, which depends both on the engine speed and the position of the carburetor throttle, but also responds selectively to variations in the said differential pressure owing to the fact that the inertia of the inertia-block causes its relative displacement with respect to the pressureresponsive member during such pressure variations.

According to a preferred form of embodiment, the movable pressure-responsive member is constituted by a piston sliding sealingly in a tubular body, the two mutually opposite ends of which are respectively connected to vacuum takeoffs or derivations opening into the inlet manifold and into the carburetor, the said piston being advantageously subjected to the antagonistic actions of two springs of unequal stiffness. The said piston serves as a slide valve and normally closes the outlet into the regulator body of a lateral fuel-inlet connection.

Thus, the feeding of the idling jet with fuel depends on the differential pressure between the carburetor and the inlet manifold.

Moreover and advantageously, the said piston is hollow, its lateral wall being provided with at least one orifice adapted to be connected to the fuel-inlet connection, and its end wall on the carburetor vacuum side being provided with an orifice which normally communicates with a connection carried by the corresponding end of the regulator body and connected with the idling jet.

The aforesaid inertia-block is advantageously slidingly mounted in the piston between two suspension springs and carries a valve which is preferably mounted resiliently and serves to close the said orifice.

Thus, any abrupt variation of the position of the piston, resulting for instance from the increase in differential pressure caused by the abrupt closing of the carburetor throttle in case of deceleration, results in the closing of the piston orifice by the valve carried by the inertia-block, thus instantaneously interrupting the supply of fuel to the carburetor idling jet, more especially as the said piston serves as a suction pump and prevents the flow towards the said jet of the fuel contained in the regulator body through the conduit connecting it to the idling jet.

The invention will be better understood and other objects, characteristics and advantages thereof will appear as the following description proceeds, with reference to the appended drawing given solely by way of example illustrating one form of embodiment of the invention and wherein:

FIG. 1 is a diagrammatic axial sectional view of an idling regulator according to the invention:

FIG. 2 is a diagram showing the mounting of the regulator of FIG. 1.

The idling regulator 10 illustrated in FIG. 1 comprises a tubular body 11 provided with a medial lateral connection 12 and closed by two covers 13, 14 forming connections, a second lateral connection 15 being arranged in proximity to the cover 13. The regulator 10 contains a piston 20 constituting a movable pressure-responsive member in which is slidingly mounted an inertia-block 30.

The diagram of FIG. 2 shows the mounting of the regulator 10 in the feeding device of an intemal-combustion engine, which comprises essentially a carburetor C shown in a very diagrammatized manner. The carburetor comprises essentially a venturi V into which opens the main jet GP fed by a flow chamber N connected with the fuel rank R through a conduit 1; downstream of the venturi V is arranged a rotary throttle P controlled by the accelerator pedal of the vehicle. The regulator 10 is inserted in the feeding circuit of the idling jet GR of the carburetor C, its connection 12 being to this end connected to the flow chamber N through a conduit 2, while its connection 13 is connected to the idling jet GR through a conduit 3; the end connection 14 is connected through a conduit 4 to a vacuum takeofi' D4 in the inlet manifold T of the engine, while the opposite lateral connection 15 is connected through a conduit 5 to a vacuum takeoff D5 located immediately upstream of the closing position of the throttle P of the carburetor C.

As shown in FIG. I, the pressure-responsive member of the regulator 10 is constituted by a hollow piston 20 provided in the vicinity of its ends with guiding bearings sliding on the inner wall of the body 11 and in the vicinity of its center with two sealing bears 21, 21' spaced axially and contracting the inner wall of the body 11 on either side of the outlet of the connection 12; the annular grooves thus constituted between the bears 21, 21' communicate with the internal space of the piston 20 through a series of orifices 22 passing through the lateral wall of the latter. Two springs 23, 24 of unequal stiffness resting respectively upon the covers l3, 14 of the body 11 exert on the piston 20 antagonistic forces which are respectively proportionate to the vacuum in the carburetor, transmitted through the connection 15, and to the vacuum in the inlet manifold, transmitted through the connection 4. The end on the side of the connection 15 of the piston 20 is closed by a cover 26 adapted to be applied against a corresponding seat 16 of the cover 13 of the regulator body 11, the said cover 26 being provided with a central orifice 27 opening in the axis of the connection carried by the cover 13.

In the hollow piston 20 slides the inertia-block 30 constituted by a tubular member the outer periphery of which is provided with two guiding collars 31, 31' and a series of longitudinal slots 32 enabling the free passage of. the fuel introduced into the piston 20 through the orifices 22. The inertiablock 30 is normally maintained in a medial equilibrium position by two suspension springs 33, 34 resting respectively upon the cover 26 and the bottom of the piston 20. Opposite the cover 26, the inertia-block 30 is provided with an opening enabling the passage of the rod 35 of a valve 37 adapted to close the orifice 27 of the cover 26 of the piston, the head 36 of the said rod being normally maintained applied against the bottom of the inertia-block 30 by a spring 38 resting upon a plug 39 closing the said inertia-block.

The operation of the regulator according to the invention is as follows.

Under the normal conditions of operation, the vacuums prevailing in the carburetor C and in the manifold T are substantially in the same ratio as the stiffnesses of the springs 23 and 24, so that the piston 20 takes a steady equilibrium position in which the sealing bearing 21 closes the outlet of the fuel inlet connection 12, so that the idling jet GR is not fed. The engine speed at which the piston 20 takes this equilibrium position is of course determined by way of experiment for each type of engine, a simple replacement of the springs 23, 24 enabling besides to adapt one and the same regulator to engines of different tubes.

In case of operating speed variation while the engine is running at slow speed or in case of steady idling, the relative increase of the vacuum prevailing in the manifold displaces the piston 20 in such a manner that its sealing bearing 21 uncovers at least partially'the outlet of the connection 12. The fuel therefore passes into the piston 20 through the orifices 22, passes round the inertia-block 30 and its valve 37 and then flows out through the orifice 27 to be conveyed to the idling jet through the conduit 3 provided on the connection 13. Under such conditions, it will be noted on the one hand that the vacuum in the carburetor is not sufficient to suck the fuel through the connection and that any relative variation of the vacuum in the inlet manifold causes a resultant displacement of the piston and therefore a modulation of the flow of fuel provided to the idling jet.

In case of abrupt deceleration, for instance when the driver releases the accelerator pedal, the abrupt increase in vacuum in the inlet manifold T applied to the connection 14 causes an abrupt displacement of the piston 20 against the action of the spring 24. Owing to the inertia of the inertia-block 30 the valve 37 of the inertia-block closes the orifice 27 of the piston cover 26, thus instantaneously interrupting the supply of fuel to the idling jet. At the same time, the piston 20 acting as a suction pump prevents the fuel located at the bottom of the regulator body from flowing through the connection 13 towards the idling jet. For increased safety, the bearing 21 of the piston 20 at the end of its stroke closes the outlet of the fuel inlet connection 12.

The motion of the piston 20 back to its position of equilibrium occurs automatically under the action of the spring 24. It should however be noted in this respect that after an abrupt deceleration the vacuum in the manifold T decreased relatively slowly, according to a well-known curve, thus ensuring the progressive return of the piston to its position of equilibrium.

Such a progressive motion enables to avoid an abrupt injection of an inadmissible amount of fuel into the carburetor C through the medium of the vacuum conduit 5.

The resilient mounting of the valve 37 on the inertia-block 30 has for its purpose to dampen impacts and vibrations in operation and, possibly, to prolong the time of closing of the orifice 27, since the said mounting enables the valve to remain applied to its seat for the fraction of time during which the piston 20 returns to its position of equilibrium.

Of course, the invention is by no means limited to the form of embodiment described and illustrated, which has been given by way of example only. In particular, it comprises all the means constituting technical equivalents to the means described as well as their combinations, should the latter be carried out according to the spirit of the invention.

What is claimed is: 1. Idling regulator for an internal-combustion engine carburetor, adapted to substantially interrupt the feeding of fuel to an idling jet of said carburetor in case of abrupt deceleration of said engine, characterized in that it comprises an inertiablock resiliently connected to a movable pressure responsive member subjected to the pressure difference between said carburetor and the inlet manifold of said engine, and valve means for operatively controlling the feeding of fuel of said idling jet, said valve means being selectively actuated by the displacements of said pressure-responsive member and said inertia-block in response to variations of said pressure difference.

2. Idling regulator according to claim 1, characterized in that said movable pressure-responsive member is constituted by a piston sliding sealingly in a tubular body, the opposite ends of which are respectively connected to vacuum takeoffs opening into said inlet manifold and into said carburetor.

3. Idling regulator according to claim 2, characterized in that said piston is subjected to the antagonistic actions of two return springs of unequal stiffness respectively located in said opposite ends of said tubular body.

4. Idling regulator according to claim 3, characterized in that said piston serves as a slide valve which normally closes the opening into said tubular body of a lateral fuel inlet connection.

5. Idling regulator according to claim 4, characterized in that said piston is hollow, its lateral wall being provided with at least one orifice adapted to be selectively communicated with said lateral fuel inlet connection, and its end wall on the carburetor vacuum side being provided with an orifice which normally communicates with the fuel outlet connection extending through the corresponding end of said body and connected to said idling jet.

6. Idling regulator according to claim 5, characterized in that said inertia-block slides in said piston between two suspension springs.

7. Idling regulator according to claim 6, characterized in that said inertia-block carriers a valve member adapted to close said orifice in said end wall of said piston.

8. Idling regulator according to claim 7, characterized in that said valve member is resiliently carried by said inertiablock.

gl iyfifi STATES ?ATENT iatent No. 3;,63l 8 -A Dated ig 1972 M .u f Inventor (s) Ciauae Chavam It is certified that error appears in the above-identifiefi patent and that said Letters Patent are hereby corrected as shown below:

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EDWARD MwLETCHEfi J39 ROBERT GOTTSGHALK gtti {Eff-ice Commissioner of Patents USCOMM-DC' 6037 6-P69 FORM o-1050 (10-59) U.S. GOVERNIIIENT PRiNTiNG OFFICE: I969 O355-334 

1. Idling regulator for an internal-combustion engine carburetor, adapted to substantially interrupt the feeding of fuel to an idling jet of said carburetor in case of abrupt deceleration of said engine, characterized in that it comprises an inertia-block resiliently connected to a movable pressure responsive member subjected to the pressure difference between said carburetor and the inlet manifold of said engine, and valve means for operatively controlling the feeding of fuel of said idling jet, said valve means being selectively actuated by the displacements of said pressure-responsive member and said inertia-block in response to variations of said pressure difference.
 2. Idling regulator according to claim 1, characterized in that said movable pressure-responsive member is constituted by a piston sliding sealingly in a tubular body, the opposite ends of which are respectively connected to vacuum takeoffs opening into said inlet manifold and into said carburetor.
 3. Idling regulator according to claim 2, characterized in that said piston is subjected to the antagonistic actions of two return springs of unequal stiffness respectively located in said opposite ends of said tubular body.
 4. Idling regulator according to claim 3, characterized in that said piston serves as a slide valve which normally closes the opening into said tubular body of a lateral fuel inlet connection.
 5. Idling regulator according to claim 4, characterized in that said piston is hollow, its lateral wall being provided with at least one orifice adapted to be selectively communicated with said lateral fuel inlet connection, and its end wall on the carburetor vacuum side being provided with an orifice which normally communicates with a fuel outlet connection extending through the corresponding end of said body and connected to said idling jet.
 6. Idling regulator according to claim 5, characterized in that said inertia-block slides in said piston between two suspension springs.
 7. Idling regulator according to claim 6, characterized in that said inertia-block carriers a valve member adapted to close said orifice in said end wall of said piston.
 8. Idling regulator according to claim 7, characterized in that said valve member is resiliently carried by said inertia-block. 